Polarization Manipulation in Silicon Wire Waveguides

Abstract

Polarization control techniques in silicon photonic wire waveguide systems have been studied experimentally. A simple directional coupler with an oblong silicon core works as a polarization splitter, which can separate two orthogonal modes with a polarization extinction ratio (PER) of over 10dB for the C-band. An asymmetric core configuration produces polarization rotation during light propagation. Double- and dual-core polarization rotators have been designed, fabricated and characterized. The dualcore type was found to have some advantages regarding fl exibility of design and material absorption. The PER of the dual-core rotator is also more than 10dB. These polarization control devices have potential to be used in ultrahigh-speed data transmission with polarization multiplexing technique.